How to Check if User entered text contains http:// in Javascript

Question

I have a setup like, My website ask the user for entering a URL. Sometimes user enters like http://google.com/ and other times google.com, but my application supports URL with http:// or https://,
I tried this:

var a = document.getElementById('tinput').value;
if (a.indexOf(escape('http://')) < 0 && a.indexOf(escape('https://')) < 0){
b = 'http://' + a;
document.getElementById('tinput').value = b;
}
document.getElementById("urlfrm").submit();

But this dint work. It always adds http:// to all the URL even if they contain the same. What to do?

did you try removing escape() ? because it converts your https:// into https%3A// — xdevel
– xdevel, Commented Jul 3, 2012 at 9:19

VirMatrix · Accepted Answer · 2012-07-03 09:18:20Z

2

Try

var a = document.getElementById('tinput').value;
if (a.indexOf('http://') == -1 && a.indexOf('https://') == -1){
b = 'http://' + a;
document.getElementById('tinput').value = b;
document.getElementById("urlfrm").submit();
} else {
document.getElementById("urlfrm").submit();
}

answered Jul 3, 2012 at 9:18

VirMatrix

516 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Mitya · Accepted Answer · 2012-07-03 09:44:46Z

1

Try this:

var field = document.getElementById('tinput');
if (!/^https?:\/\//.test(field.value)) field.value = 'http://'+field.value;

A couple of points to note:

your current check allows for http(s):// to be anywhere in the string - you should check for it at the start only
in the interests of code readability, and because the only value under zero that indexOf() can return is -1, it's better to check for that explicitly, rather than < 0
you're creating a global variable (b) for no reason
don't escape - as xdevel said in his comment, this will mean you check for an encoded version of the string, not the string itself

edited Jul 3, 2012 at 9:44

answered Jul 3, 2012 at 9:22

Mitya

34.7k15 gold badges70 silver badges126 bronze badges

Comments

SpacedMonkey · Accepted Answer · 2012-07-03 09:23:43Z

0

You can do this simply with regular expressions, well worth learning about them.

if ( a.match("^https?://") ) {
    alert("a is a url");
}

answered Jul 3, 2012 at 9:23

SpacedMonkey

2,7731 gold badge17 silver badges17 bronze badges

Collectives™ on Stack Overflow

How to Check if User entered text contains http:// in Javascript

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related